Fluidic systems are currently used in many industries. Devices that incorporate fluidic systems include but are not limited to DNA analyzers, clinical chemistry analyzers, high pressure liquid chromatography analyzers, lab-on-a-chip devices, and a myriad of micro and macro fluidics sample handling and preparation systems. These fluidic systems typically rely on discrete fluidic components such as tubings, fittings, pumps, valves and precision dispensing equipment to treat, modify, inject and otherwise manipulate analytes and diluents for the purposes of treating, reacting, detecting or quantifying the analyte in solution. Currently available fluidics systems are designed to make and break fluidic connections in a sequential, adjacent discrete fashion. Therefore, conventional fluidic systems operate like a scroll or a cassette tape, moving fluids sequentially with no provision to randomly access discontiguous fluid conduits without first encountering adjacent fluid conduits. This drawback greatly limits the complexity of operations that may be completed with a single device or combinations of components.
Other key disadvantages of conventional fluidic designs include carry-over of analyte from one discrete channel to another upon switching fluidic paths. For example, consider a fluidic stream selector rotary valve that is commonly known in the art with three positions A, B and C that connect the three distinct fluid paths A, B and C to a common outlet Z. When the valve is in position A, fluid A is in fluid communication with outlet Z. Likewise, when the valve is in position B, fluid B is in fluid communication with outlet Z. During an actuation event in which position A is switched to position C, the device must traverse position B, potentially contaminating fluid B with fluid A. This problem is inherent in the sequential operation of the rotary design and is commonly termed “sample carry over” in the art.
Another example of a similar drawback which characterizes conventional fluidic designs can be illustrated with a conventional rotary injection valve that has two positions A and B. In this case, position A is at low fluidic pressure and incorporates a fluidic conduit A that is loaded with analyte A. Position B is at high fluidic pressure and incorporates a fluidic conduit B. When the valve switches from position A to position B, the analyte A in the fluid conduit a empties into the fluid conduit B, thereby allowing the analyte to be loaded into conduit A at low pressure and injected into conduit B at high pressure. The problem with this device is that analyte A can adsorb or stick to fluid conduit A and not fully empty into fluid conduit B. This causes carry over and an error in the measured amount of analyte A in an injected sample. Another disadvantage of conventional fluidic design devices includes cross talk, which occurs when fluid leaks between various positions in a valve (as in the example above, in which fluid A leaks into fluid B).
There are manifolds currently available on the market that integrate fluidic components and connections and are found in many clinical analyzers. However, these fluidic systems are not characterized by a random access operating sequence and cannot provide dynamic interchangeable fluidic seals and configurable elements.